<template>
  <section class="todoapp">
    <!-- 除了驼峰, 还可以使用-转换链接 -->
    <TodoHeader @addTask="addTaskFn" :list="list"></TodoHeader>
    <TodoMain :list="showList" @del="delFn"></TodoMain>
    <TodoFooter
      @changeType="typeFn"
      :type="getSel"
      :len="showList.length"
      @clearTask="clearFn"
    ></TodoFooter>
  </section>
</template>

<script>
// 1.0 样式引入
import "./styles/base.css"
import "./styles/index.css"

import TodoHeader from "./components/TodoHeader";
import TodoMain from "./components/TodoMain";
import TodoFooter from "./components/TodoFooter";


export default {
  components: {
    TodoHeader,
    TodoMain,
    TodoFooter,
  },
  data() {
    return {
      list: [
        { id: 100, name: "吃饭", isDone: true },
        { id: 101, name: "睡觉", isDone: false },
        { id: 102, name: "打豆豆", isDone: true },
      ],
      // list: JSON.parse(localStorage.getItem('todolist')) || [],
      getSel: 'all',  //all 全部   yes  已完成  no  未完成
    };
  },

  computed: {
    showList() {
      if (this.getSel === 'yes') {
        return this.list.filter(item => item.isDone)
      } else if (this.getSel === 'no') {
        return this.list.filter(item => !item.isDone)
      } else {
        return this.list
      }
    }
  },
  methods: {
    addTaskFn(task) {
      let id = this.list.at(-1).id ? this.list.at(-1).id + 1 : 100
      this.list.push({
        id: id,
        name: task,
        isDone: false
      })
    },
    delFn(id) {
      // let index = this.list.findIndex(item => item.id === id)
      //   this.list.splice(index, 1)

      // filter 数组方法如果id相同  就筛除这一项
      this.list = this.list.filter(item => item.id !== id)
    },
    typeFn(type) {
      this.getSel = type
    },
    clearFn() {
      this.list = this.list.filter(item => !item.isDone)
    }
  },
  watch: {
    list:{
      deep: true,
      handler() {
        localStorage.setItem('todolist', JSON.stringify(this.list))
      }
    }
  },
};
</script>